DTC Troubleshooting

DTC Troubleshooting: P2647

DTC P2647: Rocker Arm Oil Pressure Switch Circuit High Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Reading and Clearing Diagnostic Trouble Codes

1. Check the engine oil level.

Is the engine oil level OK?
YES - Go to step 2.

NO - Adjust the engine oil to the proper level, then go to step 17.


2. Turn the ignition switch to ON (II).

3. Clear the DTC with the HDS.

4. Do the VTEC TEST in the INSPECTION MENU with the HDS.
NOTE: If a DTC is stored during the VTEC TEST, check the DTC's MENU. If DTC P2647 indicated, go to step 6. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.

Is the result OK?
YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the rocker arm oil pressure switch and the PCM.

NO - Go to step 5.


5. Check the result of step 4.
- Rocker arm oil pressure switch Failure

- Rocker arm oil pressure switch Open

- Rocker arm oil pressure switch SIG Line Open

- Rocker arm oil pressure switch GND Line Open

Is the test result any of the above?
YES - Go to step 6.

NO - Check for poor connections or loose terminals at the rocker arm oil pressure switch. If it is OK, replace the rocker arm oil control solenoid, Service and Repair then go to step 17.


6. Turn the ignition switch to LOCK (0).

7. Disconnect the rocker arm oil pressure switch 2P connector.

8. At the rocker arm oil pressure switch side, check for continuity between rocker arm oil pressure switch 2P connector terminals No. 1 and No. 2.

Is there continuity?
YES - Go to step 9.

NO - Replace the rocker arm oil pressure switch, Service and Repair then go to step 16.






9. Turn the ignition switch to ON (II).

10. Measure the voltage between rocker arm oil pressure switch 2P connector terminal No. 1 and body ground.

Is there battery voltage?
YES - Repair open in the wire between the rocker arm oil pressure switch and G101, then go to step 13.

NO - Go to step 11.






11. Measure the voltage between PCM connector terminal A23 and body ground.

Is there battery voltage?
YES - Repair open in the wire between the PCM (A23) and the rocker arm oil pressure switch, then go to step 12.

NO - Go to step 19.






12. Turn the ignition switch to LOCK (0).

13. Reconnect the all connectors.

14. Turn the ignition switch to ON (II).

15. Reset the PCM with the HDS.

16. Do the PCM idle learn procedure. PCM Idle Learn Procedure

17. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P2647 indicated?
YES - Check for poor connections or loose terminals at the rocker arm oil pressure switch and the PCM, then go to step 1.

NO - Go to step 18.


18. Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 17, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the rocker arm oil pressure switch and the PCM, then go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.


19. Turn the ignition switch to LOCK (0).

20. Reconnect all connectors.

21. Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM. Reading and Clearing Diagnostic Trouble Codes

22. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P2647 indicated?
YES - Check for poor connections or loose terminals at the rocker arm oil pressure switch and the PCM. If the PCM was updated, substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the PCM was substituted, go to step 1.

NO - Go to step 23.


23. Monitor the OBD STATUS for DTC P2647 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. Service and Repair If any other Pending or Confirmed DTCs were indicated in step 22, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the rocker arm oil pressure switch and the PCM. If the PCM was updated, substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.